Ab crunch back extension exercise machine



FIG. 1 is a front view of the ab crunch back extension exercise machine in accordance with the present invention;

FIG. 2 is a left side view of the present invention;

FIG. 3 is a back view of the present invention;

FIG. 4 is a right side view of the present invention;

FIG. 5 is a top view of the present invention;

FIG. 6 is a front perspective view of the present invention; and,

FIG. 7 is a back perspective view of the present invention. 

The ornamental design for an ab crunch back extension exercise machine, as shown and described. 